Lock-snap contact for making electrical connections.



J. 0. HEINZB, Jn.

LOOK SNAP CONTACT FOR MAKING ELBOTRIOAL CONNEOTIONS.

' APPLICATION FILED 1:20.13, 1910.

1,039,392, Patented Sept. 24,1912,

JOHN OTTO HEINZE, JR., LOWELL, MASSACHUSETTS.

Specification of Letters Patent.

LOCK-SNAP CONTACT FOR MAKING ELECTRICAL CONNECTIONS.

Patented Sept. 24, 1912.

Application filed December 13, 1910. Serial No. 597,031.

10 The object of my invention is to provide for a high tension wire and an electrical clement, say a spark plug, a secure and quickly operated slip connection.

In the drawings illustrating the principle of my. invention, and the best method now known to me of embodying the same in operative structure, Figure 1 is a perspectivc view showing one feature of my invention; viz. a stepped-cone head for the high tension terminal of a spark plug. Fig. 2 is a similar view showing a further feature residing in a compressible spring lock-clip, to engage the head shown in Fig. 1. Fig. 3 is an elevation of the head. Fig. 4 is a plan view of the clip. Fig. 5 is a longitudinal section of the head and clip when in operative engagement. Fig, 6 is an elevation of the clip, in Fig. 5. Fig. 7 is an under plan of whatis shown on section line 6 Fig, 5. Fig. 8 is an elevation of a modified form of head.

An electrical element 1, say a spark plug for an internal combustion engine, has a spool shaped external metallic contact nut 2, threaded upon its high tension terminal wire 3. This nut 2, Fig. 3, has two opposite series of cylindrical ofi'sets or steps, the smallest step 4, being common to both series and forming what may be termed the spindle; the next larger steps 5, 5, the locksteps; while the largest steps 6, 6, may be called the shoulder-steps; all of which clearly appear in Figs. 1, 3 and 5..

An insulated high tension wire 7, Figs.

45 2 and 5, as from a magneto, is provided with a slip spring terminal, comprising a pair of C shaped metal contact plates 8, 8,

the rear portions of which are secured to the high tension wire 7, in any suitable way, for

50 example, that shown in Figs. 4 and 5. These two plates 8, 8, when held in operative position, see Fig. 5, are substantially parallel; and they have therein, in alinement, two side openings, each of which is formed by a. cir- 55 cular hole 9 and an entrance or mouth 10 connecting it with the outside edge' of its respective plate 8. The width of these ontrances 10, and the diameter of the circular holes 9 correspond with the diameter of the spindle 4 of the spool, and the diameter of the next larger pair of steps, 2'. e. lock-steps 5, 5; hence the distance between the metal plates 8, 8, Fig. 5, when they are substan tially parallel, equals the length of the spindle 4, or the distance between the locksteps '5, 5. Normally, if the.contact plates are not in use, they are not parallel but are at an acute angle, as shown in Fig. 6.

Figs. 1 and 2 illustrate how the electrical connections may be made. By pressing the plates 8, 8, together with. the fingers, the mouths 10, 10, of the openings permit the passage of the spindle 4 of the spool into the circular portionst), 9, and upon the release of the compressed plates, they spring outward, embrace the circular lock-steps of the head, as is clearly shown in Fig. 5, and are arrested bv the parallel faces of the shoulders 6, 6; the spring plates 8, 8, and the spark plug 1 becoming securely locked together in electrical contact, because the diameter of the lock-steps. 5,. 5, is greater than the, width of thelnouths 10, 10, of the openings, as appears inFigs. 3,14, 5 and 7. To unlock the connections, the plates 8, 8, Figs. 2 and 5, are pressed together, as indicated in dotted lines, in Fig. 5, become disengaged from the lock-steps 5, 5, and the horns of the plates, which now embrace the common step or spool 4;"may be pulled away from the plug, for the reason that the mouths 10, 10, of the openings and the diameter of the common ste or spool are the same; the severed parts ta king the positions shown in Figs; 1, 2 and 6.

In order that a spark lug, employingthe common binding nut 2 or wire connection, may use my lock snap plates, these look steps may be cut in the binding nut, as already explained; or, in case it is desirable to use only my style of spring connection, then the binding nut 2 and the terminal nut 11, shown in Figs. 1 and 5, maybe made in a single piece 12 embodying the modification illustrated in Fig. 7.

Desiring to protect my invention in the broadest manner legally possible, what I claim is: A spool shaped metallic terminal provided with steps, for an electrical element; a pair of spring plates compressible toward each opening movements of the spring plates in e' other and connected to a high tension wire, the direction of the axis of the spool. it

each plate having a side opening designed In testimony whereof I aflix my signature I to permit the plate to obe'moved lnto posiin presence of two witnesses.

tion and embrace one of the steps' the months of these openings, being .in \ividth JOHN OTCPO N larger than the diameter of the spool but Witnesses:

smaller than the diameter of the steps;'and F. J. V. ,DAKIN;

shoulders outside of the steps to limit the UNIAO.

Copies of this patent may be obtained for five cents each, by eddressing the "fibmmibsloner of Patents, Weshington, D. 9. 

